Volute trapped vortex combustor assembly

ABSTRACT

A combustor assembly is generally provided. The combustor assembly includes a volute wall extended annularly around a combustor centerline. The volute wall is extended at least partially as a spiral curve from a circumferential reference line around the combustor centerline. The volute wall defines a combustion chamber therewithin. An annular inner wall is extended at least partially along a lengthwise direction from the volute wall. An annular outer wall is extended at least partially along the lengthwise direction from the volute wall. The inner wall and the outer wall are each separated along a radial direction from the combustor centerline. A primary flow passage is defined between the inner wall and the outer wall in fluid communication from the combustion chamber.

FIELD

The present subject matter relates generally to combustion assemblies.More particularly, the present subject matter relates to trapped vortexcombustor assemblies.

BACKGROUND

Gas turbine engines generally include combustion sections in whichcompressed air is mixed with a fuel and ignited to generate highpressure, high temperature combustion gases that then flow downstreamand expand to drive a turbine section coupled to a compressor section, afan section and/or a load device. Conventional combustion sections arechallenged to burn a variety of fuels of various caloric values.Conventional combustion sections are also challenged to reduceemissions, such as nitric oxides, unburned hydrocarbons, and smoke,while also maintaining or improving combustion stability across a widerrange of fuel/air ratios, air flow rates, and inlet pressures. Stillfurther, conventional combustion sections are challenged to achieve anyor all of these criteria while maintaining or reducing longitudinaland/or radial dimensions and/or part quantities.

Therefore, there exists a need for a combustion section that may improveemissions output and improve combustion stability across a wider rangeof fuel/air ratios, air flow rates, and inlet pressures while alsoreducing combustion section dimensions.

BRIEF DESCRIPTION

Aspects and advantages of the invention will be set forth in part in thefollowing description, or may be obvious from the description, or may belearned through practice of the invention.

A combustor assembly is generally provided. The combustor assemblyincludes a volute wall extended annularly around a combustor centerline.The volute wall is extended at least partially as a spiral curve from acircumferential reference line around the combustor centerline. Thevolute wall defines a combustion chamber therewithin. An annular innerwall is extended at least partially along a lengthwise direction fromthe volute wall. An annular outer wall is extended at least partiallyalong the lengthwise direction from the volute wall. The inner wall andthe outer wall are each separated along a radial direction from thecombustor centerline. A primary flow passage is defined between theinner wall and the outer wall in fluid communication from the combustionchamber.

In various embodiments, the combustor assembly further includes aprimary fuel injector. The volute wall defines one or more fuelinjection openings through which the primary fuel injector is extendedat least partially into the combustion chamber. In one embodiment, areference chord is defined from the volute wall. The primary fuelinjector is extended at least partially into the combustion chamber atan acute angle relative to the reference chord. In another embodiment,the primary fuel injector is extended at least partially into thecombustion chamber at a tangent angle relative to the volute wall andthe combustor centerline.

In still various embodiments, a portion of the volute wall and a portionof the outer wall together define a secondary flow passage therebetween.The volute wall and the outer wall together define one or more secondaryoutlet openings adjacent to the combustion chamber and in fluidcommunication therewith. In various embodiments, the outer wall definesone or more secondary inlet openings in fluid communication with thesecondary flow passage and the secondary outlet opening. In oneembodiment, the secondary flow passage defines a decreasing crosssectional area from approximately the secondary inlet opening toapproximately the secondary outlet opening. In another embodiment, thecombustor assembly further includes a secondary fuel injector extendedat least partially into the secondary flow passage through the secondaryinlet opening.

In one embodiment, the volute wall is extended from a first radiusdisposed approximately at the secondary outlet opening to a secondradius disposed approximately at the inner wall. The first radius isgreater than the second radius.

In another embodiment, the secondary flow passage is extended at leastpartially annularly relative to the combustor centerline.

In still yet another embodiment, a secondary flow passage wall isextended to the portion of the volute wall and the portion of the outerwall together defining the secondary flow passage. The secondary flowpassage wall defines two or more discrete secondary flow passages inadjacent circumferential arrangement around the combustor centerline.

In various embodiments, the outer wall defines a tertiary openingtherethrough adjacent to the primary flow passage. In one embodiment,the combustor assembly further includes a tertiary fuel injectorextended at least partially through the tertiary opening at the outerwall. In another embodiment, the tertiary fuel injector is extended atleast partially at a tangent angle relative to the outer wall and thecombustor centerline.

In still various embodiments, the volute wall defines one or more volutewall openings therethrough in fluid communication with the combustionchamber. In one embodiment, the volute wall defines a volute wallpassage extended to the volute wall opening, the volute wall passageextended from a pressure plenum surrounding the volute wall, the innerwall, and the outer wall. In another embodiment, a second referencechord is defined from the volute wall. The volute wall defines thevolute wall passage at an acute angle relative to the reference chord.

In one embodiment, the combustor assembly further includes a diffusercase surrounding the volute wall, the inner wall, and the outer wall.The diffuser case includes an inner diffuser wall defined inward of theinner wall and the volute wall along the radial direction. An outerdiffuser wall is defined outward of the outer wall and the volute wallalong the radial direction. The diffuser case is extended at leastpartially along a lengthwise direction. The diffuser case defines apressure plenum surrounding the volute wall, the outer wall, and theinner wall.

In another embodiment, the combustor assembly further includes a secondinner wall disposed inward of the inner wall along the radial direction.The second inner wall is extended at least partially along thelengthwise direction, and an inner cooling flow passage is definedbetween the second inner wall and the inner wall.

In still another embodiment, the combustor assembly further includes asecond outer wall disposed outward of the outer wall along the radialdirection, the second outer wall is extended at least partially alongthe lengthwise direction, and an outer cooling flow passage is definedbetween the outer wall and the second outer wall.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a schematic cross sectional view of an exemplary gas turbineengine incorporating an exemplary embodiment of a combustor assembly;

FIG. 2 is an axial cross sectional view of an exemplary embodiment of acombustor assembly of the combustion section of the gas turbine enginegenerally provided in FIG. 1;

FIG. 3 is a perspective view of a portion of an exemplary embodiment ofa combustor assembly of the combustion section of the gas turbine enginegenerally provided in FIG. 1; and

FIG. 4 is an axial cross sectional view of another exemplary embodimentof a combustor assembly of the combustion section of the gas turbineengine generally provided in FIG. 1.

Repeat use of reference characters in the present specification anddrawings is intended to represent the same or analogous features orelements of the present invention.

DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

As used herein, the terms “first”, “second”, and “third” may be usedinterchangeably to distinguish one component from another and are notintended to signify location or importance of the individual components.

The terms “upstream” and “downstream” refer to the relative directionwith respect to fluid flow in a fluid pathway. For example, “upstream”refers to the direction from which the fluid flows, and “downstream”refers to the direction to which the fluid flows.

Embodiments of a volute combustor assembly that may improve emissionsoutput and combustion stability are generally provided. The volutecombustor assembly embodiments generally provided herein generallydefines a trapped vortex combustor. Various embodiments further define adual-staged toroidally stabilized primary combustion zone at leastpartially isolated from one or more downstream combustion zones producedby one or more secondary and tertiary fuel injectors. The volute wallsof the combustor assembly at least partially partition the primarycombustion zone from the one or more combustion zones defined downstreamof the primary combustion zone. The volute combustor assembly maygenerally provide a more compact combustor assembly, thereby decreasingoverall gas turbine engine dimensions and weight, and improving gasturbine engine efficiency and performance. The volute combustor assemblymay further improve turndown or part-load performance in gas turbineengines and reduce emissions, such as oxides of nitrogen, carbondioxide, or particulates (e.g., smoke).

Referring now to the drawings, FIG. 1 is a schematic partiallycross-sectioned side view of an exemplary gas turbine engine defining ahigh by-pass turbofan engine 10 herein referred to as “engine 10” as mayincorporate various embodiments of the present disclosure. Althoughfurther described below with reference to a turbofan engine, the presentdisclosure is also applicable to gas turbine engines in general,including turbomachinery in general such as turbojet, turboprop, andturboshaft gas turbine engines, including marine and industrial turbineengines and auxiliary power units. The present disclosure is furtherapplicable to propulsion systems for apparatuses including rockets,missiles, etc., such as ramjets, scramjets, etc. The engine 10 generallydefines an axial direction A, a radial direction R1 relative to an axialcenterline axis 12 extended there through for reference purposes, and acircumferential direction Cl extended relative to the centerline axis12. In general, the engine 10 may include a fan assembly 14 and a coreengine 16 disposed downstream from the fan assembly 14.

The core engine 16 may generally include a substantially tubular outercasing 18 that defines an annular inlet 20. The outer casing 18 encasesor at least partially forms, in serial flow relationship, a compressorsection having a booster or low pressure (LP) compressor 22, a highpressure (HP) compressor 24, a combustion section 26, a turbine section31 including a high pressure (HP) turbine 28, a low pressure (LP)turbine 30 and a jet exhaust nozzle section 32. A high pressure (HP)rotor shaft 34 drivingly connects the HP turbine 28 to the HP compressor24. A low pressure (LP) rotor shaft 36 drivingly connects the LP turbine30 to the LP compressor 22. The LP rotor shaft 36 may also be connectedto a fan shaft 38 of the fan assembly 14. In particular embodiments, asshown in FIG. 1, the LP rotor shaft 36 may be connected to the fan shaft38 by way of a reduction gear 40 such as in an indirect-drive orgeared-drive configuration. In other embodiments, the engine 10 mayfurther include an intermediate pressure (IP) compressor and turbinerotatable with an intermediate pressure shaft.

As shown in FIG. 1, the fan assembly 14 includes a plurality of fanblades 42 that are coupled to and that extend radially outwardly fromthe fan shaft 38. An annular fan casing or nacelle 44 circumferentiallysurrounds the fan assembly 14 and/or at least a portion of the coreengine 16. In one embodiment, the nacelle 44 may be supported relativeto the core engine 16 by a plurality of circumferentially-spaced outletguide vanes or struts 46. Moreover, at least a portion of the nacelle 44may extend over an outer portion of the core engine 16 so as to define abypass airflow passage 48 therebetween.

Referring now to FIG. 2, an axial cross sectional view of a combustorassembly 50 of the combustion section 26 is generally provided. Thecombustor assembly 50 includes a volute wall 100 extended annularlyaround a combustor centerline 11. The volute wall 100 is extended atleast partially as a spiral curve from a circumferential reference line95 around the combustor centerline 11. The volute wall 100 defines acombustion chamber 62 inward of the volute wall 100. An annular innerwall 110 is extended at least partially along a lengthwise direction Lfrom the volute wall 100. An annular outer wall 120 is extended at leastpartially along the lengthwise direction L from the volute wall 100. Theinner wall 110 and the outer wall 120 are separated along a radialdirection R2 from the combustor centerline 11. A primary flow passage 70is defined between the inner wall 110 and the outer wall 120 in fluidcommunication from the combustion chamber 62.

It should be appreciated that in various embodiments, the combustorcenterline 11 may be the same as the axial centerline 12 of the engine10. However, in other embodiments, the combustor centerline 11 may bedisposed at an acute angle relative to the axial centerline 12. Stillfurther, the combustor centerline 11 may be disposed at a tangentrelative to the axial centerline 12. As such, in various embodiments,the lengthwise direction L may be the same as the axial direction A orgenerally co-directional or co-planar. However, in other embodiments,the lengthwise direction L is defined relative to the disposition of thecombustor centerline 11, such as co-directional, which may be defined ata different direction relative to the axial direction A of the engine10.

In various embodiments, the combustor assembly 50 further includes aprimary fuel injector 210. The volute wall 100 defines one or more fuelinjection openings 103 through which the primary fuel injector 210 isextended at least partially into the combustion chamber 62. In oneembodiment, a reference chord 96 is defined from the volute wall 100.The primary fuel injector 210 is extended at least partially into thecombustion chamber 62 at an acute angle 97 relative to the referencechord 96.

In another embodiment, the primary fuel injector 210 is extended atleast partially into the combustion chamber 62 at a tangent anglerelative to the volute wall 100 and the combustor centerline 11. Forexample, the primary fuel injector 210 may be disposed at a tangentangle such that a flow of liquid or gaseous fuel is deposited into thecombustion chamber 62 at least partially along a circumferentialdirection C2 relative to the combustor centerline 11 (shown in FIG. 3)within the combustion chamber 62.

In still various embodiments, the primary fuel injector 210 may extendat least partially into the combustion chamber 62 at a compound angle ofaxial, radial, and azimuthal components relative to the combustionchamber 62.

In various embodiments, the primary fuel injector 210 deposits a flow ofliquid or gaseous fuel into the combustion chamber 62 to define aprimary combustion zone 61 within the combustion chamber 62. In stillvarious embodiments, the primary fuel injector 210 and the combustionchamber 62 define an annular trapped vortex or toroidally stabilizedprimary combustion zone 61. The trapped vortex primary combustion zone61 may be defined stoichiometrically lean or rich. In one embodiment,the fuel at the combustion chamber 62 from the primary fuel injector 210may be premixed with oxidizer. In another embodiment, the fuel andoxidizer may be separate (i.e., diffusion). In still variousembodiments, a combination of diffuser and premixed fuel/oxidizer mayenter the primary combustion zone 61 defined in the combustion chamber62.

Referring now to FIG. 3, a perspective view of a portion of thecombustor assembly 50 of FIG. 2 is generally provided. Referring toFIGS. 2-3, a portion 101 of the volute wall 100 and a portion 121 of theouter wall 120 together define a secondary flow passage 105therebetween. The volute wall 100 and the outer wall 120 together defineone or more secondary outlet openings 106 adjacent to the combustionchamber 62. The second outlet opening 106 is in fluid communication withthe primary flow passage 70. In one embodiment, the second outletopening 106 is more specifically in fluid communication with thecombustion chamber 62. The outer wall 120 further defines one or moresecondary inlet openings 107 in fluid communication with the secondaryflow passage 105 and the secondary outlet opening 106.

In one embodiment of the combustor assembly 50, the secondary flowpassage 105 is extended at least partially annularly relative to thecombustor centerline 11. In other embodiments, such as generally shownin FIG. 3, a secondary flow passage wall 122 is extended to the portion101 of the volute wall 100 and the portion 121 of the outer wall 120.The secondary flow passage wall 122, the portion 101 of the volute wall100, and the portion 121 of the outer wall 120 together define thesecondary flow passage 105 as a discrete passage. The secondary flowpassage wall 122 defines two or more discrete secondary flow passages105 in an adjacent circumferential arrangement around the combustorcenterline 11.

In one embodiment, the annular trapped vortex primary combustion zone 61within the combustion chamber 62 is disposed generally outward along theradial direction R2 relative to the primary flow passage 70 extendedbetween the inner wall 110 and the outer wall 120. For example, thecombustion chamber 62 is generally stacked and at least partiallypartitioned from the primary flow passage 70 via the portions 101, 121of the volute wall 100 and the outer wall 120 extended to define thesecondary flow passage 105.

Referring back to FIG. 2, in various embodiments, the secondary flowpassage 105 defines a decreasing cross sectional area from approximatelythe secondary inlet opening 107 to approximately the secondary outletopening 106. The decreasing cross sectional area may generally define anozzle accelerating a flow of fluid through the secondary flow passage105 to the combustion chamber 62. In various embodiments, the flow offluid is a liquid or gaseous fuel (further described below), a flow ofoxidizer (e.g., air), or a flow of inert gas or combinations thereof

In one embodiment, the secondary flow passage 105, at least in part, mayprovide a flow of oxidizer to help define at least one passage providinga flow of oxidizer to the volute combustion chamber 62 helping to drivethe trapped vortex or toroidal stabilization of the primary combustionzone 61 at the combustion chamber 62.

In another embodiment, such as further discussed below, the combustorassembly 50 further defines one or more fuel injection locationsdownstream of the primary combustion zone 61 at the combustion chamber62, such as between the trapped vortex primary combustion zone 61 and adownstream exit of the combustor assembly 50. Similarly as the primaryfuel injector 210 and the primary combustion zone 61, the one or moredownstream fuel injection locations may be defined as stoichiometricallylean or rich, or combinations thereof. Still further, the one or morefuel injection locations may define a diffusion or premixed fuel andoxidizer, or combinations thereof. In various embodiments, thedownstream fuel injector locations further discussed below may bedefined as actively-controlled fueled dilution of combustion gasesexiting the combustor assembly 50. In still various embodiments, theprimary fuel injector 210, one or more of the downstream fuel injectors(e.g., secondary fuel injector 220, tertiary fuel injector 230), orcombinations thereof, may be controlled to selectively provide fuel orfuel/oxidizer mixture to the combustion chamber 62, the primary flowpassage 70, or both, to provide a desired residence time of thefuel/oxidizer mixture when forming the combustion gases 86.

Referring now to FIG. 4, an axial cross sectional view of the combustionsection 26 is generally provided. In the embodiment shown in FIG. 4, thecombustor assembly 50 may further include a secondary fuel injector 220extended at least partially into the secondary flow passage 105 throughthe secondary inlet opening 107. The secondary fuel injector 220 isconfigured to deposit a flow of liquid or gaseous fuel into thesecondary flow passage 105 to egress into the combustion chamber 62. Assuch, the secondary flow passage 105 in fluid communication with theprimary flow passage 70, or more specifically, the combustion chamber62, defines a secondary fuel/oxidizer injection port generallydownstream (along the primary flow passage 70) of the primary fuelinjector 210. The secondary flow passage 105 may egress a fuel into thecombustion chamber 62 to mix and ignite to form a secondary combustionzone downstream of the primary combustion zone 61, such as shownschematically at circle 66.

Referring still to FIG. 4, in various embodiments of the combustorassembly 50, the volute wall 100 extends from a first radius 91 disposedapproximately at the secondary outlet opening 106 to a second radius 92disposed approximately at the inner wall 110. The second radius 92 isgenerally greater than the first radius 91. As such, the volute wall 100may generally define a scroll wall defining an annular volute combustionchamber 62.

Referring now to FIGS. 2 and 4, the combustor assembly 50 may furtherdefine a tertiary opening 123 through the outer wall 120. The tertiaryopening 123 is defined adjacent to the primary flow passage 70. Forexample, the tertiary opening 123 is generally downstream of thecombustion chamber 62. More specifically, the tertiary opening 123 maybe defined through the outer wall 120 downstream of the secondary outletopening 106.

In various embodiments, the combustor assembly 50 further includes atertiary fuel injector 230 extended at least partially through thetertiary opening 123 at the outer wall 120. In one embodiment, thetertiary fuel injector 230 is extended at least partially at a tangentangle relative to the outer wall 120 and the combustor centerline 11,such as to deposit a flow of liquid or gaseous fuel at least partiallyalong the circumferential direction C2 (shown in FIG. 3) relative to thecombustor centerline 11. The tertiary fuel injector 230 may egress aflow of fuel into the primary flow passage 70 to mix and ignite to forma tertiary combustion zone downstream of the primary combustion zone 61,such as shown schematically at circle 67.

Referring now to FIGS. 2-4, in various embodiments, the volute wall 100defines one or more volute wall openings 102 therethrough in fluidcommunication with the combustion chamber 62. The volute wall openings102 permit a flow of oxidizer into the combustion chamber 62 to drivethe trapped vortex therewithin. In one embodiment, the vortex-drivingoxidizer may be premixed with a fuel separate from the primary fuelinjector 210 such as to create an at least partially premixed hybridtrapped vortex zone in the combustion chamber 62.

Referring now to FIG. 4, in still various embodiments, the volute wall100 defines a volute wall passage 104 extended to the volute wallopening 102. The volute wall passage 104 is extended from a diffusercavity or pressure plenum 64 (e.g., compressor exit pressure or P3)surrounding the volute wall 100, the inner wall 110, and the outer wall120. In one embodiment, a second reference chord 93 is defined from thevolute wall 100. The volute wall 100 defines the volute wall passage 104at an acute angle 94 relative to the reference chord 96. In anotherembodiment, the volute wall passage 104 may define a decreasing crosssectional area from the pressure plenum 64 to the combustion chamber 62such as to accelerate a flow of oxidizer into the combustion chamber 62.The accelerated flow of oxidizer and/or the acute angle 94 at which theflow of oxidizer enters the combustion chamber 62 may further promotetoroidal stabilization of the combustion gases at the primary combustionzone 61 within the combustion chamber 62.

Referring still to FIG. 4, the combustor assembly 50 may further includea second inner wall 115 disposed inward of the inner wall 110 along theradial direction R2. The second inner wall 115 is extended at leastpartially along the lengthwise direction L. An inner cooling flowpassage 117 is defined between the second inner wall 115 and the innerwall 110. The inner cooling flow passage 117 provides a flow of oxidizerfrom the pressure plenum 64 to downstream of the combustor assembly 50.For example, the inner cooling flow passage 117 may provide a flow ofoxidizer from the pressure plenum 64 to a turbine nozzle of a turbinesection 31. The inner cooling flow passage 117 may further define finsor nozzles, or varying cross sectional areas, such as to define aninducer accelerating a flow of oxidizer toward the downstream end. Theaccelerated flow of oxidizer may further provide thermal attenuation orheat transfer to at least one of the inner wall 110, the second innerwall 115, or a downstream component of the engine 10 (e.g., turbinenozzle, turbine rotor, turbine secondary flowpath, etc.).

In another embodiment, the combustor assembly 50 may further include asecond outer wall 125 disposed outward of the outer wall 120 along theradial direction R2. The second outer wall 125 is extended at leastpartially along the lengthwise direction L. An outer cooling flowpassage 127 is defined between the outer wall 120 and the second outerwall 125. Similarly as described in regard to the inner cooling flowpassage 117, outer cooling flow passage 127 provides a flow of oxidizerfrom the pressure plenum 64 toward downstream of the combustor assembly50. For example, the outer cooling flow passage 127 may provide a flowof oxidizer from the pressure plenum 64 to a turbine nozzle of a turbinesection 31. The outer cooling flow passage 127 may further define finsor nozzles, or varying cross sectional areas, such as to define aninducer accelerating a flow of oxidizer toward the downstream end.

In various embodiments, one or more of the volute wall 100, or the innerwall 110, the outer wall 120 may include a plurality of orificestherethrough to enable a portion of oxidizer to flow from the secondaryflow passage 105, the inner cooling passage 117, or the outer coolingpassage 127, respectively, or the pressure plenum 64. into the primaryflow passage 70, such as to adjust or affect an exit temperatureprofile, or circumferential distribution thereof (e.g., pattern factor).The orifices may define dilution jets, cooling nuggets or louvers,holes, or transpiration. In still various embodiments, the plurality oforifices may provide thermal attenuation (e.g., cooling) to one or moreof the volute wall 100, the inner wall 110, or the outer wall 120.

Referring still to FIG. 4, the combustor assembly 50 may further includea pressure vessel or diffuser case 80 surrounding the volute wall 100,the inner wall 110, and the outer wall 120. The diffuser case 80includes an inner diffuser wall 81 defined inward of the inner wall 110and the volute wall 100 along the radial direction R2. An outer diffuserwall 82 is defined outward of the outer wall 120 and the volute wall 100along the radial direction R2. The diffuser case 80 is extended at leastpartially along the lengthwise direction L or along the axial directionA. The diffuser case 80 defines the pressure plenum 64 surrounding thevolute wall 100, the outer wall 120, and the inner wall 110.

During operation of the engine 10, as shown in FIGS. 1-4 collectively, avolume of air as indicated schematically by arrows 74 enters the engine10 through an associated inlet 76 of the nacelle 44 and/or fan assembly14. As the air 74 passes across the fan blades 42 a portion of the airas indicated schematically by arrows 78 is directed or routed into thebypass airflow passage 48 while another portion of the air as indicatedschematically by arrow 80 is directed or routed into the LP compressor22. Air 80 is progressively compressed as it flows through the LP and HPcompressors 22, 24 towards the combustion section 26.

As shown in FIG. 2, the now compressed air as indicated schematically byarrows 82 flows through the combustor assembly 50. A liquid or gaseousfuel is deposited into the combustion chamber 62 via the primary fuelinjector 210. The fuel and compressed air 82 are mixed and burned toproduce combustion gases 86 (shown in FIG. 1). More specifically, thefuel and air are mixed and ignited in the combustion chamber 62 at theprimary combustion zone 61 and toroidally stabilized via the compressedair 82 entering the combustion chamber 62 via the secondary flow passage105, the volute wall openings 102, or both. In various embodiments, suchas shown in FIG. 3, the secondary fuel injector 220 provides additionalfuel through the secondary flow passage 105 to further mix with air andcombustion gases downstream of the primary combustion zone 61. Thecombustion gases then flow through the primary flow passage 70 towardthe turbine section 31. In various embodiments, the combustor assembly50 including the tertiary fuel injector 230 further deposits fuel to theprimary flow passage 70 to mix with the combustion gases 86 downstreamof the primary combustion zone 61.

Referring still to FIGS. 1-4, the combustion gases 86 generated in thecombustion chamber 62 flow from the volute wall 100 into the HP turbine28, thus causing the HP rotor shaft 34 to rotate, thereby supportingoperation of the HP compressor 24. As shown in FIG. 1, the combustiongases 86 are then routed through the LP turbine 30, thus causing the LProtor shaft 36 to rotate, thereby supporting operation of the LPcompressor 22 and/or rotation of the fan shaft 38. The combustion gases86 are then exhausted through the jet exhaust nozzle section 32 of thecore engine 16 to provide propulsive thrust.

It should be appreciated that, in various embodiments, openingsgenerally defined herein, such as, but not limited to, the volute wallopening 102, the secondary outlet opening 106, the secondary inletopening 107, and one or passages, such as, but not limited to, thevolute wall passage 104 and the secondary flow passage 105, the innercooling flow passage 117, and the outer cooling flow passage 127, mayeach define one or more cross sectional areas including, but not limitedto racetrack, circular, elliptical or ovular, rectangular, star,polygonal, or oblong, or combinations thereof. Still further, theaforementioned passages may define variable cross sectional areas, suchas decreasing, increasing, or combination thereof, such asconvergent/divergent. The variable cross sectional areas may definefeatures providing an accelerated flow, changes in pressure, or changesin orientation of flow, such as along a circumferential direction,radial direction, or axial direction, or combinations thereof.

All or part of the combustor assembly may be part of a single, unitarycomponent and may be manufactured from any number of processes commonlyknown by one skilled in the art. These manufacturing processes include,but are not limited to, those referred to as “additive manufacturing” or“3D printing”. Additionally, any number of casting, machining, welding,brazing, or sintering processes, or any combination thereof may beutilized to construct the combustor assembly 50 separately or integralto one or more other portions of the combustion section 26. Furthermore,the combustor assembly 50 may constitute one or more individualcomponents that are mechanically joined (e.g. by use of bolts, nuts,rivets, or screws, or welding or brazing processes, or combinationsthereof) or are positioned in space to achieve a substantially similargeometric, aerodynamic, or thermodynamic results as if manufactured orassembled as one or more components. Non-limiting examples of suitablematerials include high-strength steels, nickel and cobalt-based alloys,and/or metal or ceramic matrix composites, or combinations thereof.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A combustor assembly, the combustor assemblycomprising: a volute wall extended annularly around a combustorcenterline, and wherein the volute wall is extended at least partiallyas a spiral curve from a circumferential reference line around thecombustor centerline, and wherein the volute wall defines a combustionchamber therewithin; an annular inner wall extended at least partiallyalong a lengthwise direction from the volute wall; and an annular outerwall extended at least partially along the lengthwise direction from thevolute wall, wherein the inner wall and the outer wall are separatedalong a radial direction from the combustor centerline, and wherein aprimary flow passage is defined between the inner wall and the outerwall in fluid communication from the combustion chamber.
 2. Thecombustor assembly of claim 1, further comprising a primary fuelinjector, wherein the volute wall defines one or more fuel injectionopenings through which the primary fuel injector is extended at leastpartially into the combustion chamber.
 3. The combustor assembly ofclaim 2, wherein a reference chord is defined from the volute wall, andwherein the primary fuel injector is extended at least partially intothe combustion chamber at an acute angle relative to the referencechord.
 4. The combustor assembly of claim 2, wherein the primary fuelinjector is extended at least partially into the combustion chamber at atangent angle relative to the volute wall and the combustor centerline.5. The combustor assembly of claim 1, wherein a portion of the volutewall and a portion of the outer wall together define a secondary flowpassage therebetween, and wherein the volute wall and the outer walltogether define one or more secondary outlet openings adjacent to thecombustion chamber and in fluid communication therewith.
 6. Thecombustor assembly of claim 5, wherein the outer wall defines one ormore secondary inlet openings in fluid communication with the secondaryflow passage and the secondary outlet opening.
 7. The combustor assemblyof claim 6, wherein the secondary flow passage defines a decreasingcross sectional area from approximately the secondary inlet opening toapproximately the secondary outlet opening.
 8. The combustor assembly ofclaim 6, further comprising a secondary fuel injector extended at leastpartially into the secondary flow passage through the secondary inletopening.
 9. The combustor assembly of claim 5, wherein the volute wallextends from a first radius disposed approximately at the secondaryoutlet opening to a second radius disposed approximately at the innerwall, and wherein the first radius is greater than the second radius.10. The combustor assembly of claim 5, wherein the secondary flowpassage is extended at least partially annularly relative to thecombustor centerline.
 11. The combustor assembly of claim 5, wherein asecondary flow passage wall is extended to the portion of the volutewall and the portion of the outer wall together defining the secondaryflow passage, wherein the secondary flow passage wall defines two ormore discrete secondary flow passages in adjacent circumferentialarrangement around the combustor centerline.
 12. The combustor assemblyof claim 1, wherein the outer wall defines a tertiary openingtherethrough adjacent to the primary flow passage.
 13. The combustorassembly of claim 12, further comprising a tertiary fuel injectorextended at least partially through the tertiary opening at the outerwall.
 14. The combustor assembly of claim 13, wherein the tertiary fuelinjector is extended at least partially at a tangent angle relative tothe outer wall and the combustor centerline.
 15. The combustor assemblyof claim 1, wherein the volute wall defines one or more volute wallopenings therethrough in fluid communication with the combustionchamber.
 16. The combustor assembly of claim 15, wherein the volute walldefines a volute wall passage extended to the volute wall opening, thevolute wall passage extended from a pressure plenum surrounding thevolute wall, the inner wall, and the outer wall.
 17. The combustorassembly of claim 16, wherein a second reference chord is defined fromthe volute wall, and wherein the volute wall defines the volute wallpassage at an acute angle relative to the reference chord.
 18. Thecombustor assembly of claim 1, further comprising a diffuser casesurrounding the volute wall, the inner wall, and the outer wall, thediffuser case comprising an inner diffuser wall defined inward of theinner wall and the volute wall along the radial direction, and an outerdiffuser wall defined outward of the outer wall and the volute wallalong the radial direction, and wherein the diffuser case is extended atleast partially along a lengthwise direction, the diffuser case defininga pressure plenum surrounding the volute wall, the outer wall, and theinner wall.
 19. The combustor assembly of claim 1, further comprising asecond inner wall disposed inward of the inner wall along the radialdirection, wherein the second inner wall is extended at least partiallyalong the lengthwise direction, and wherein an inner cooling flowpassage is defined therebetween.
 20. The combustor assembly of claim 1,further comprising a second outer wall disposed outward of the outerwall along the radial direction, wherein the second outer wall isextended at least partially along the lengthwise direction, and whereinan outer cooling flow passage is defined therebetween.